S1, E8: Devastated by the state of her relationship with Nate and still dealing with the guilt from a recent indiscretion, Blair puts on a happy face for her 17th birthday party and attempts to hide the truth from her friends. Hoping to ease the tension between Serena and Vanessa (recurring guest star JESSICA SZOHR), Dan takes Vanessa to Blair's party so the girls can have some bonding time, but this only ends up making Serena more uncomfortable. Meanwhile, Jenny brings her mom (recurring guest star SUSAN MISNER) home for a surprise visit, but Rufus may not be ready to forgive and forget. And Nate's parents ask him to make a huge sacrifice in order to salvage the business of his father, who faces charges of embezzlement and fraud.